1. Field of the Invention
Example embodiments generally relate to a fixing device and an image forming apparatus, and more particularly, to a fixing device for fixing a toner image on a recording medium and an image forming apparatus incorporating the fixing device.
2. Description of the Related Art
Related-art image forming apparatuses, such as copiers, facsimile machines, printers, or multifunction printers having at least one of copying, printing, scanning, and facsimile functions, typically form an image on a recording medium according to image data. Thus, for example, a charger uniformly charges a surface of a photoconductor; an optical writer emits a light beam onto the charged surface of the photoconductor to form an electrostatic latent image on the photoconductor according to the image data; a development device supplies toner to the electrostatic latent image formed on the photoconductor to render the electrostatic latent image visible as a toner image; the toner image is directly transferred from the photoconductor onto a recording medium or is indirectly transferred from the photoconductor onto a recording medium via an intermediate transfer belt; finally, a fixing device applies heat and pressure to the recording medium bearing the toner image to fix the toner image on the recording medium, thus forming the image on the recording medium.
Such fixing device may include a fixing roller and a pressing roller pressed against the fixing roller to form a fixing nip therebetween through which the recording medium bearing the toner image is conveyed. The fixing roller is heated by a heater disposed inside the fixing roller. As the fixing roller and the pressing roller rotate and convey the recording medium bearing the toner image through the fixing nip, the fixing roller and the pressing roller apply heat and pressure to the recording medium, thus fixing the toner image on the recording medium. The recording medium bearing the fixed toner image discharged from the fixing nip is conveyed toward the outside of the image forming apparatus while guided by a guide disposed downstream from the fixing device in a recording medium conveyance direction.
However, the guide may be subject to condensation when the cool fixing device is warmed up for fixing operation during cold start, that is, when the fixing device is powered on in the cold morning or heated to a given fixing temperature in a cool environment after a standby mode in which the fixing device waits for a next print job at a temperature lower than the given fixing temperature. If the guide is adhered with water droplets, the water droplets may move onto the recording medium passing over the guide, damaging the toner image on the recording medium.
To address this problem, a plurality of solutions is proposed. For example, as a first solution, the guide may be attached with a heat generator that warms the guide. As a second solution, the guide may be in contact with a conductive heat pipe that warms the guide. As a third solution, a conveyance face of the guide over which the recording medium is conveyed may mount conductive wiring that warms the guide or may be coated with a material that absorbs water droplets adhered to the guide.
However, those solutions to prevent condensation of the guide may require a complex mechanism or a material manufactured at increased costs, failing to prevent condensation of the guide efficiently.